Bayh said Indiana would be among the states that would bear a disproportionate share of the cost of meeting the requirement. He said a fairer system would be offering tax credits for producing power from renewable sources.

The standard of 15 percent renewable energy or efficiency gains by 2021 is significantly weaker than President Obama’s preferred standard of 25 percent by 2025. Sen. Sam Brownback (R-KS) and Sen. Bob Corker (R-TN) joined 11 Democrats in support of the standard, and Sen. Mary Landrieu (D-LA) did not vote.